by dinnerstick » Thu Oct 15, 2015 10:10 am
1. the pump pushes the grain up against the top screen, which can slide up or down along the post. so when the grain pipe is not completely packed the grain bed is still set upside-down at the top, and the wort runs very clear like a well established gravity-fed grain bed. the difference is that the final lautering is done by gravity in the reverse direction, so the bed sort of has to re-set at the bottom of the pipe. therefore you get some particulates in the kettle, but really not very much. if you want to run completely clear wort to the fermenter you just need to settle the wort after the boil, which of course you would do anyways. in my opinion it's a total non-issue.
2. stepped mashes, there are countless arguments on the topic, and everyone has an opinion, some supported by facts and others not. so i won't touch that. but there are certain grain bills; high percentages of unmalted oat or wheat for example, that benefit from various lower temp rests like beta-glucan and protein. also i love to do overnight mashes, with relatively normal sacc rests and extended mashout, this requires an automated stem mash while i'm snoring away.
3. about 5000 years